The massive slag heaps dot the landscape as reminders of coal-mining heydays. Not everyone finds them pretty. But for the most part, folks see them as a point of nostalgia — and sometimes a very high point, as in hundreds of feet tall.

Mostly north of Peoria, coal companies sunk shafts into the earth in the late 19th century. While pulling out the precious coal, they had to do something with the byproducts — clay, shale, sulfur and coal waste — usually just piling it up, for decade after decade.

In many communities, the coal veins went empty in the early decades of the 20th century. When those companies left, towns struggled — though many survive today.

As for their jumbos, some eventually disappeared. Mark’s were leveled for safety reasons, while Minonk’s vanished when used for fill to create overpasses for Interstate 39. Others — such as those in Toluca, Ladd and Wenona — remain as mountainous anomalies amid the flat croplands.

The Village of Roanoke sports the jumbo nearest Peoria, . Mining began there in 1881, lasting until 1940. The 100-foot-tall mound is known to many as Mt. Jumbo, which many of the 2,000-some residents used to climb — on foot or bicycle — in their youth.

But no more. The jumbo, which is privately owned, has been closed for safety reasons. Still, the U.S. flag remains up top, a proud accent to the heaping source of civic pride.